diff --git a/README.md b/README.md
index ac2ac4b96a..27347dc488 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-Spring Integration <img src="https://build.spring.io/plugins/servlet/buildStatusImage/INT-B40X">
+Spring Integration <img src="https://build.spring.io/plugins/servlet/buildStatusImage/INT-B41">
 ==================
 
 # Checking out and Building
@@ -9,6 +9,8 @@ To check out the project and build from source, do the following:
     cd spring-integration
     ./gradlew build
 
+**NOTE:** While Spring Integration runs with Java SE 6 or higher, a Java 8 compiler is required to build the project.
+
 If you encounter out of memory errors during the build, increase available heap and permgen for Gradle:
 
     GRADLE_OPTS='-XX:MaxPermSize=1024m -Xmx1024m'
diff --git a/src/reference/asciidoc/preface.adoc b/src/reference/asciidoc/preface.adoc
index bfe113c4f4..9a598fadc1 100644
--- a/src/reference/asciidoc/preface.adoc
+++ b/src/reference/asciidoc/preface.adoc
@@ -10,15 +10,20 @@ This section details the compatible http://www.oracle.com/technetwork/java/javas
 [[supported-java-versions]]
 === Compatible Java Versions
 
-For _Spring Integration_*4.1.x*, the *minimum* compatible Java version is *Java SE 6*.
+For _Spring Integration_ *4.2.x*, the *minimum* compatible Java version is *Java SE 6*.
 Older versions of Java are not supported.
 
-_Spring Integration_*4.1.x* is also compatible with *Java SE 7* as well as *Java SE 8*.
+_Spring Integration_ *4.2.x* is also compatible with *Java SE 7* as well as *Java SE 8*.
+
+Certain features (such as `Optional<?>` payloads and `CompletableFuture` gateway method return types) require Java 8.
+
+While the jars are compatible with Java 6, Java 8 is required to build the project.
+see https://github.com/spring-projects/spring-integration#checking-out-and-building[Checking out and Building].
 
 [[supported-spring-versions]]
 === Compatible Versions of the Spring Framework
 
-_Spring Integration_*4.1.x* requires _Spring Framework_*4.1.4* or later.
+_Spring Integration_ *4.2.x* requires _Spring Framework_ *4.2.0* or later.
 
 [[code-conventions]]
 === Code Conventions